Fiberoptic Probe Visualizes Early Cancers

In its first laboratory tests on human tissue, a light-based probe nearly instantaneously detected the earliest signs of cancer in cells that line internal organs.
If the early success of the optical biopsy is established through clinical trials, such a device could ultimately provide a particular advantage for early diagnosis, treatment, and prevention of many types of cancer, according to the researchers. Most tumors begin in the body's epithelial cells, which line the mucous membranes in the lungs, esophagus, and gut.
"About 85% of all cancers start in the epithelium. It may be, for example, brain cancer that causes a patient's death, but that cancer might have originated in the colon or other site of epithelial tissue,” said Dr. Adam Wax, professor of biomedical engineering at Duke University (Durham, NC, USA). "Being able to detect pre-cancer in epithelial tissues would therefore help prevent all types of cancer by catching it early, before it has a chance to develop further or spread.”
In some cases, the technique, known as fa/LCI (frequency-domain angle-resolved low coherence interferometry), might eventually enable clinicians and their patients to avoid removal of tissue for biopsy, according to Dr. Wax. In other instances, he added, fa/LCI could help clinicians target suspicious cells during a conventional biopsy procedure, making it less likely for a cancerous lesion to evade detection.
Dr. Wax and his former graduate student John Pyhtila reported in the March 2007 issue of the journal Gastrointestinal Endoscopy that their fiberoptic device effectively differentiated between healthy and precancerous digestive tissue taken from the stomach and esophagus of three patients known to have a precancerous form of a condition called Barrett's esophagus. In less than a second, their fa/LCI-enhanced version of an endoscope, instruments used to visualize internal organs, provided the clinical information required for diagnosis.
"Our initial study is very promising,” Dr. Wax said of the findings. "We looked at tissue removed from just a handful of patients and were able to get 100% sensitivity. We could detect pre-cancer in the esophagus and distinguish it from normal tissue like you would find in the stomach.”
The fa/LCI device detects abnormalities in the nucleus, or central component, of cells, through changes in the way laser light scatters. "The size and shape of cell nuclei are powerful indicators of this precancerous condition called dysplasia, which literally means ‘bad growth',” Dr. Wax said. "Typically, nuclei are a fairly consistent size. However, when you go down the road toward cancer, you get irregular and enlarged cell nuclei. Our device lets us measure those changes with much better accuracy than any imaging technique.”
His team plans to begin a small clinical trial of the advanced endoscope in collaboration with researchers at Duke University Medical Center. The researchers are also conducting animal studies to evaluate the feasibility of incorporating fa/LCI into instruments for examining the colon, lung, and other organs. Based on a study in laboratory hamsters, Dr. Wax and Duke postdoctoral researcher Kevin Chalut reported in the February 2007 issue of the journal Cancer Epidemiology Biomarkers & Prevention that the technique might also be used in the identification of early lung cancer.
Dr. Wax and his colleagues have launched a company, called Oncoscope, to pursue the commercial development of fa/LCI devices. If all goes as planned, a new and improved endoscope might be ready for the clinic in three to five years, Dr. Wax reported.


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